868 resultados para Heating and ventilation industry


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After the 10 regional water authorities of England and Wales were privatized in November 1989, the successor WASCs (water and sewerage companies) faced a new regulatory regime that was designed to promote productivity growth while simultaneously improving drinking water and environmental quality. As legally mandated quality improvements necessitated a costly capital investment programme, the industry's economic regulator – the Office of Water Services – implemented a RPI + K pricing system, designed to compensate the WASCs for their capital investment programme while also encouraging faster rates of productivity growth. This paper considers the relative effects of privatization and regulation on productivity growth in the industry using both non-parametric and parametric methods to provide a crosscheck on the robustness of the results. While there is evidence that labour productivity improved after privatization, there is no evidence that privatization led to a growth in TFP (total factor productivity). However, there is some evidence of a small increase in the rate of TFP growth in the aftermath of a substantial tightening of the regulatory regime that took place in 1995. These results, therefore, are consistent with evidence from other research that privatization, in the absence of effective competition and/or regulation, is not necessarily associated with improved economic performance.

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In the present work, the more important parameters of the heat pump system and of solar assisted heat pump systems were analysed in a quantitative way. Ideal and real Rankine cycles applied to the heat pump, with and without subcooling and superheating were studied using practical recommended values for their thermodynamics parameters. Comparative characteristics of refrigerants here analysed looking for their applicability in heat pumps for domestic heating and their effect in the performance of the system. Curves for the variation of the coefficient of performance as a function of condensing and evaporating temperatures were prepared for R12. Air, water and earth as low-grade heat sources and basic heat pump design factors for integrated heat pumps and thermal stores and for solar assisted heat pump-series, parallel and dual-systems were studied. The analysis of the relative performance of these systems demonstrated that the dual system presents advantages in domestic applications. An account of energy requirements for space and hater heating in the domestic sector in the O.K. is presented. The expected primary energy savings by using heat pumps to provide for the heating demand of the domestic sector was found to be of the order of 7%. The availability of solar energy in the U.K. climatic conditions and the characteristics of the solar radiation here studied. Tables and graphical representations in order to calculate the incident solar radiation over a tilted roof were prepared and are given in this study in section IV. In order to analyse and calculate the heating load for the system, new mathematical and graphical relations were developed in section V. A domestic space and water heating system is described and studied. It comprises three main components: a solar radiation absorber, the normal roof of a house, a split heat pump and a thermal store. A mathematical study of the heat exchange characteristics in the roof structure was done. This permits to evaluate the energy collected by the roof acting as a radiation absorber and its efficiency. An indication of the relative contributions from the three low-grade sources: ambient air, solar boost and heat loss from the house to the roof space during operation is given in section VI, together with the average seasonal performance and the energy saving for a prototype system tested at the University of Aston. The seasonal performance as found to be 2.6 and the energy savings by using the system studied 61%. A new store configuration to reduce wasted heat losses is also discussed in section VI.

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The increasing need for maintenance, repair, and overhaul (MRO) organizations to meet customers' demands in quality and reduced lead times is key to its survival within the aviation industry. Furthermore, with the unpredictability in the global market and difficulties with forecasting characteristic of the MRO industry there is an increased need for the reevaluation of the operation models of organizations within this sector. However, severe economic turmoil and ever-increasing global competition introduce the opportunity for the adoption of a resilient, tried, and tested business operation model such as 'Lean'. In order to understand this concept, its long-term viability, and its application within the aerospace MRO sector fully, this paper presents the state-of-the-art in terms of the adoption of Lean within the MRO industry by carrying out a systematic review of the literature. This paper establishes the common perception of Lean by the MRO industry and the measurable progress that has been made on the subject. Some issues and challenges are also highlighted including the misconceptions that arise from the direct transference of the perception of Lean from other industrial sectors into the aerospace MRO industry. The 'enablers and inhibitors' of Lean within the aviation industry are also discussed. This paper exposes the scarcity of the literature and the general lagging behind of the industry to the adoption of the Lean paradigm and thus highlights areas where further research is required. © 2011 Authors.

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After the ten Regional Water Authorities (RWAs) of England and Wales were privatized in November 1989, the successor Water and Sewerage Companies (WASCs) faced a new regulatory regime that was designed to promote economic efficiency while simultaneously improving drinking water and environmental quality. As legally mandated quality improvements necessitated a costly capital investment programme, the industry's economic regulator, the Office of Water Services (Ofwat), implemented a retail price index (RPI)+K pricing system, which was designed to compensate the WASCs for their capital investment programme while also encouraging gains in economic efficiency. In order to analyse jointly the impact of privatization, as well as the impact of increasingly stringent economic and environmental regulation on the WASCs' economic performance, this paper estimates a translog multiple output cost function model for the period 1985–1999. Given the significant costs associated with water quality improvements, the model is augmented to include the impact of drinking water quality and environmental quality on total costs. The model is then employed to determine the extent of scale and scope economies in the water and sewerage industry, as well as the impact of privatization and economic regulation on economic efficiency.